Design of bezel sealing for pressureproof cases



y 22, 19 5 J. s. HELLEN 2,376,593

DESIGN OF BEZEL SEALING FOR PRESSURE PROOF CASES Filed Oct. 9, 1945ATTUENEY IN VEN TOR.

Patented May 22, 1945* DESIGN or BEZEL SEALI'NG roa PRESSURE- PROOFCASES James S. HellemRamsey, N. J.,as signor to Bendix AviationCorporation, Teterboro, N. J., a corporation of Delaware ApplicationQctoberil, 1943, Serial No. 505,695 (01.220-46) 1 5 Claim.

,The present invention .relates to casing seals and more particularlytoseals for closures, instrument bezels or the like and methods formakingsuchseals. f r

Heretofore, for example, in the production of marine, aircraftinstruments and the like, it has been the practice to provide a ribaround the surface rim of the cover, bezel or the like adapted tocompress a packing ring or interfitwithin a cooperating groove on thefacing surface rim of the casing body. Such arrangements, see Figure 1of the drawing for an example, are the cause of much trouble whenproducing seals for casings of shapes other than cylindrical, because inmaking tight seals between the cover rim and opposing casing rim, it isnecessary to machine down the facing rim surfaces of the cover and bodyto obtain a tight joint. Whileit is not as difiicult to face down around cover rim on either side of the upstanding rib on a turning latheor the like, it is practically impossible to accurately face down asquare-rectangular or non-cylindrical body on each side of such rib bymachine.

Accordingly, one object of the present invention is to eliminate theforegoing bottleneck in the production of fluid tight casing seals, sothat other than cylindrically shaped casing parts may be produced bymachine.

Another object is to provide a novel fluid tight seal for casings,whereby all opposed parts may be machined flush, so as to moreefficiently cooperate with the other elements of the seal.

Another object is to provide a novel seal for pressure proof cases orthe like comprising a novel packing distributor member designed from,and flush with a part of the cover or case.

Another object is to provide a novel bezel seal or the like for casingsincluding a plurality of cooperating grooves adapted to receive asealing medium and a cooperating sealing medium distributor countersunkin the surface rim of the bezel defined by said grooves.

Another object is to provide a novel method for producing seals betweencasing closures for casings of irregular shapes and also to provide amethod adapted to speed up production of cylindrical shapes as well.

The above and other object and advantages of the present invention willappear more fully hereinafter from a consideration ofthe detaileddescription which follows, taken together with the accompanying drawingwherein two embodiments of the invention are illustrated. It is to beexpressly understood, howeventhat the drawing is for the purpose ofillustration only and is not designed as a definition of the limits ofthe invention. Reference for this latter purpose should be had to theappended claim. r

In the drawing, wherein like reference characters refer to like partsthroughout the several views, I t

Figure 1 is a section view, broken away, representative of the priorart.

Figure 2 is a section view, broken away, of one embodiment of thepresent invention.

Figure 3 is a longitudinal section view taken through one form ofpressure proof casing produced according to the present invention,showing the closure fastened by bolt means.

- Figure 4 is a section view, broken away, of the casing sealedtogether.

Figure 5 is a top plan view of another form of easing, wherein the coveris hinged to the casing body.

More specifically, with reference to the above figures, numerallfl'represents a casing body, and 12 a cover for the same.

For example, the case may be one such as is used in the aircraftaccessory art in connection with altimeters, airspeed indicators or thelike, wherein it is desirable to have pressure proof or fluid tightcases. The'novel sealing structure for providing a fluid tight casing bythe present invention, comprises a machined level surface rim H on coverl2, which cover may have first been cast by any suitable method, so asto have formed in the said surface rim II a pair of spaced substantiallyparallel grooves l3 and Id.

In casting grooves 13 and H! in such spaced relation, an intervening ribI5 equal in height to the depth of the grooves is provided. Rib l5,therefore, is flush with the rim surface I I, which surface may now bemachined and faced down level by turning, milling or disc grinding.

The casing body It may also be cast by any suitable method, so as tohave within its rim surface it a groove IT. The groove I! is made of arelatively greater width than either groove I 3 or M, but is of lesswidth than the overall width of grooves l3, M and rib [5, for thepurpose hereinafter described. V

Within roove Il may be mounted a sealing medium, such as gasket IS. Thegasket l8, as better shown in Figure 2, is relatively thicker than thedepth of groove l1, so as to extend above the rim surface [6 of thecasing body H], which rim surface has likewise been machined level tocooperate with the opposing rim surface H of the cover H.

The cover (2 may now be secured to the casing body H) by any suitablemeans, such as hinge l9 and latch 20, shown in Figure 5, or by lugs 2|and bolts 22, as shown in Figure 3. When the cover is closed as inFigure 4, pressure is applied to the same, so that the cooperatingmachined rim surfaces II and I6 fit together, whereby rib I5 pressescentrally against the top of gasket or packing l8 and distributes thesame by compressing the gasket materially centrally to each side andinto the grooves l3 and I4 of the cover l2.

There is thus provided a novel seal and method of forming the same forcylindrical or non-cylindrical bodies by first providing accuratelymachined contacting surfaces on the cover and cas ing body withcooperating groovemeans to receive a suitable sealing medium, which isflowed, compressed or otherwise distributed to effect a fusion of themedium between the several grooves for a fluid tight seal by a built indistributor rib machined ofi flush simultaneously with the machining ofthe contracting rim surfaces.

While only'two embodiments of the invention have been illustrated anddescribed, other changes and modifications which w'iil now appear tothose skilled in the art, may be made without departing from the scopeofthe present invention. Reference is, therefore, to be had to theappended claim for a definition of the limits of the present invention.

What is claimed is:

In an instrument casing having a flange portion with a fiat outersurface, said flange defining an opening and a cover therefor having aflange with a fiat mating surface and means to press the flangestogether in registry, the readily manufacturable sealing .means whichcomprise a grooved portion of generally rectangular section in onesurface, a. belt of sealing material shaped to fit into the groove andalso of generally rectangular section with a height greater than thedepth of the groove so that a portion projects therefrom, and a pair ofmatching grooved portions in the race of the other flange disposed withtheir outer edges extending beyond those of the first men- .tionedgroove and with a rib between the matching gq'o'oves shaped to compressthe sealing material without projecting beyond the surface of itsflange, the sealing material having a compressed volume of less than thetotal fcombined volumes of the grooves, whereby the surfaces of themating flanges may be forced together with the sealing means theneffective,

JAMES S. HELLEN.

